Plasma lipoprotein (a) (LP(a)) concentrations are increased in patients with end-stage renal disease. Considering the influence of the apolipoprotein (a) (Apo(a)) polymorphism and the mode of dialysis in this prospective longitudinal study, we compared Lp(a) concentrations before and after the first 6 months of a successful kidney transplantation in 125 recipient patients. Apo(a) phenotyping was performed by using SDS-PAGE and SDS-agarose, isoforms were classified into high molecular weight (HMW) and low molecular weight (LMW). Before the graft, the Lp(a) concentrations were significantly higher in CAPD than in hemodialysis patients (p = 0.021). Six months after transplantation, Lp(a) fell in both treatment groups. This decrease occurred within both LMW and HMW but to a different extent: median relative variations were –35 and –50%, respectively (p = 0.048). Among patients with Lp(a) concentration >30 mg/dl 6 months after transplantation, 74% had LMW Apo(a) isoform while the remaining 26% had HMW isoform. Successful renal transplantation leads rapidly to a correction of Lp(a) concentrations, especially in patients treated with CAPD who have higher Lp(a) levels. The most important factor seems to be the LMW status corresponding to high Lp(a) levels.

Lp(a) from HD patients is characterized by an elevated content in TH and apo Cl11 in comparison with those of controls. Further studies are needed to evaluate in HD patients the contribution of changes in Lp(a) composition towards the metabolism of these particles.

Whole plasma from 6 normolipidemic chronic renal failure (CRF) patients undergoing hemodialysis treatment was passed through the anti-apolipoprotein (Apo) AI immunosorbent column connected to the anti-Apo B immunoaffinity column. Apo AI and B containing particles were analyzed for lipid and Apo contents. The results were compared with findings obtained in age-matched normolipidemic healthy controls. Although plasma Apo AI and All levels decreased in CRF patients, the concentrations of Apo CII, Oil, and E coeluted with Apo AI were similar to those of the controls. The slightly elevated plasma concentrations of Apo CII and Oil in the CRF patients studied were shown to be associated with Apo B containing particles. The nonretained fraction from both groups contains no Apo AI and no Apo B, but still contains lipids and other Apo such as Apo All and Apo CII. The occurrence of approximately 29% of plasma Apo E in this fraction constitutes the main abnormality found in these patients ( < 5% in controls). A two-phase electroimmunoassay shows that this Apo E did not correspond to the plasma E-AII complex. These findings show that the compositional alterations of Apo AI and Apo B containing particles in CRF patients were observed even in normolipidemic patients and suggest that the kidney may play a metabolic role in the removal of free forms of lipoprotein particles such as free Apo E.